feat(backend): add SCIM for user provisioning (#12713)

* Add SCIM
Closes https://github.com/inventree/InvenTree/issues/6339

* also test scim

* extend testing with conformance suite

* fix test suite results

* coverage completion

* fil test gaps

* add missing schema values

* fix more type issues

* fix error view

* remove route from OpenAPI

* add changelog entry

* add codeowners

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- [#12713](https://github.com/inventree/InvenTree/pull/12713) adds SCIM 2 provisioning support, allowing InvenTree to be integrated with external identity providers for user management.
+
 ### Changed
 
 ### Removed